A hydraulic apparatus control system comprises a plurality of directional control valves (12, 34, 56). Each valves serves to selectively convey pressurised fluid to a hydraulic consumer (18, 20, 22) which is detachably connected to a respective hydraulic output (71-76). A plurality of user interface devices control the valves. A terminal (50) comprises a display (52) and user input means (54, 56, 58). The display displays a graphic (61-66) associated with each hydraulic output. Each graphic includes a displayed user-definable label.
